Notable and mostly safe [meaning "shouldn't crash the game when in your pockets"] items:
Many more items are safe only when going to the shop, they provide the icons for speech bubbles after donating items, etc

About the people who corrupted their inventory by "having multiple aliens in the pocket while doing autopsies":
When the last item in your pockets is consumed, the item count is decreased (when others are consumed, the later ones are shifted left to fill the gap)
But the operatory table is bugged: its name displays a number of aliens which may be higher than how many you own, since it just checks the actual item slots without caring for how many items you have, while the minigame being accessible or not does check the number but only if you walk away and back: it's possible to play the game for more aliens than you have and underflow the item count!!
To be honest, I've not been able to replicate the crash by just going to the pockets on Desmume and Wood, but at least you now have a recovery option - if someone converts that to an AR code/you use a save backupper AND you find the game you haven't touched since 2008

021670F7: ascii string 0-terminated = your name, empty is fine (actually displays "Unnamed Sim" just on the save, blank in dialogue), moderately longer than the normal number of characters is surprisingly stable at least in the short term